Apparatus for surface hardening metal articles



Oct. 4, 1938. H. HOLLER 2,132,110

APPARATUS FOR SURFACE HARDENING METAL ARTICLES Filed Dec. 1'7, 1935 r 2 Sheets- Sheet 1 y INVENTORZ BY wal flake l V in,

ATTORNE Oct. 4,1938. f H. HOLLER ,1 1

' APPARATUS FOR SURFACE HARDENING METAL ARTICLES I Filed Dec. 17, 1935 2 Sheets-Sheet 2 l VEN on:

Patentedoct. 4, 1938 UNITED STATES APPARATUS SURFACE HARDENING METAL ARTICLES Hermann' Holler, Frankfort-on-the-Main, Germany, assignor to I. G. Farbenindustrie Aktiengesellschaft, Frankfort-on-the-Main, .Ger-

many

Application December 17,1935, Serial No. 54,923

' In Germany December 29, 1934 2 Claims.

The present invention relates to an apparatus for surface hardening metal articles.

Surface hardening of metal articles by means of the blow pipe flame has been carried outby 5 means of apparatus by which the burner is positively driven in a suitable manner over the article to be hardened. This method of hardening has also been carried out 'by apparatuswhich automatically applies the burner to the article at the beginning of its movement and removes it when this movement is finished.

For hardening numerous articles, however, it is necessary to move the burner'over the article at variable speeds, the speed in each case being 5 determined in accordance with the degree of hardness desired. Especially isthis done when hardening toothed wheels. In this application the burnermust, when placed overthe tooth to be hardened, remain in this position until the relatively cold tooth is heated sumciently. When this heating is finished the burner may be moved over the tooth flank but its velocity must be accelerated as it approaches the end of the tooth in order that overheating of this part of the toothed wheel is avoided.

When surface hardening bevel wheels, for example, where the thickness of the tooth is not constant along its width, the requirements with regard to the burner speed are more difficult to meet.

An object of the present invention is to provide a device which permits the velocity of the burner to be adjusted to suit a particular article.

My invention is practiced by moving the burner over the article to be hardened while automatically controlling its motion and driving it by operation of a driving member to which is imparted an always constant speed of rota- 40 tion. The necessary adjustment of the velocity of the moving burner is accomplished by positively changing the direction of movement of the driving member, and by transmitting the efiect of this change to the moving burner through a sliding arm between the driving member and the burner carriage.

The invention is illustrated by way of example in the accompanying drawings in which Fig. 1 is an elevation,

Fig. 2 a plan, and

Fig. 3 illustrates diagrammatically a bevel wheel to be hardened, while Fig. 3a. illustrates the cam plate used when hardening the bevel gear of Fig. 3,

55 Figs. 4 and 5 illustrate details of the drive mechanism of the arrangement shown. inFigs.

1 ,to 3. e

Referring to the drawings, a frame I carries a carriage 2 which can be adjusted to a desired position on the frame and which supports for movements thereon a burner carriage 3. In the latter carriage an arrn 4 is slidably mounted on rollers I5 in a guideway i6 for reciprocating movement ina direction transversely of the movement of theburner carriage 3. The arm is held in the guideway l6 by guide-rails II. The arm 4 is moved by awheel 5 which is driven by a motor i3, as more distinctly shown in Fig. 4-, and which is constrained by means of a solenoid I2 situated in a casing, to follow' the path of a fixed cam plate 6, the shape of Whichis determined according'to the particular requirements imposed by an article to1be hardened. The wheel 5 is driven withaconstant velocity. When, for example, a normal toothed wheel shown in Figs. 1 and 2 is to be hardened the burneris, at the commencement of the hardening process, positioned adjacent the left top edge of a wheel tooth. The whee15 at this moment is at the left rear corner ill of the cam plate 6. Wheel 5 now runs forwardly, i. e. towards the toothed wheel on the plate as indicated by an arrow in Fig. 2. As the arm 4 which carries the Wheel 5 is slidably arranged in the burner carriage 3, the burner, which is fixed to its carriage, is not moved during the forward movement of the wheel 5. As soon as the wheel 5 rounds the left front corner of the plate 6 it moves to the right as shown by the arrow in Fig. 2 at a constant velocity and thereby moves the burner to the right over the wheel tooth until the edge is reached. At the end of this movement the wheel 5 rounds the right front corner of the plate 6 and returns to its initial position by moving over the hypotenuse of the triangular cam plate 6 in the direction indicated by the inclined arrow in Fig. 2. For this purpose the driving wheel 5 is, when the heating has been finished, brought away from the action of the cam plate 6 in a manner more distinctly defined below and the burner carriage 3 is drawn back into its initial positionwith an elevated velocity by means of a weight ll.

When, instead of a normal toothed wheel a bevel wheel, as shown in Fig. 3, is to be hardened, a fixed cam plate of the shape shown at m in Fig. 3a is used; In this case the speed of the burner as it moves along a tooth is not constant but varies according to the kind of toothed wheel as can be seen from the shape of the plate at m.

. Otherwise the remaining features of the apparatus are the. same. As illustrated in Figs. 1 to 3,

the toothed wheel to be hardened is placed on an axis .which'rests on two bearings.

When the hardening process is being carried out thevcarriage I which supports the burner carriage'l is clamped to the frame I' by any suitable known means. 7 ,7

The contact of the wheel I with the surface of the fixed'cam plate I as it moves on the latter can be secured by a magnetic device. The wheel may. for example, be kept magnetized by a solenoid i2 situated above it and carried on the arm 4. The wheel will thus be constrained to remain in contact with the cam plate by magnetic attraction.

A quick return movement'of the burner may be effected by provlding a second cam plate and arranging it to be traversed by an idle running wheel which is driven by a weight. a

Figure 4 illustrates on an enlarged scale a side view of the rear part of the connecting arm 4 shown in Figure 2 on which the magnetized wheel 5 is situated, the solenoid i2 being mounted above the wheel 5 which is driven with constant velocity by means'of a motor II. A bent angle iron 9 carries the cam plate I. Above the cam plate 6 there is mounted a'further cam plate I which, in connection with the idle running wheel I effects the quick return of the burner carriage I. Figure 5 illustrates on an enlarged scale a plan view of the two cam platesl'a'nd I and the holding device 9. The cam plate I is formed in such a manner that,-when the burnercarriage '3 moves to the right, the idle running wheel I does not come in contact with the cam plate 8. At the beginning of the return movement, the idle running wheel I contacts against the cam plate .8 and removes, thereby the magnet roll I from the cam plate 6. .By the action of the weight II, the burner carriage I now "returns into its initial position with an accelerated velocity, the idle running wheel 1 running along the inclined edge of the cam plate I. As soon as the wheel I has reached the corner II, the magnet wheel I again comes into contact with the cam plate I and the further motion is now again performed by the driving motor i3.

As shown in Figures 4 and.5, the camplates O and I are fastened by a flat iron or an angle iron to the carriage 2 which is illustrated completely in Figures 1 and 2.

I claim:

1. Apparatus for heating metal articles, particularly toothed wheels .by means of the blow pipe flame for the purposeiof subsequent hardening, which comprises a burner carriage movable parallel to the surface to be heated, an arm slidably mounted on the carriage and movable;

towards and from the article, a fixed cam plate, and a driving wheelcarried on the arm, means for rotating said driving wheel with a constant velocity, a magnetic device connected with the wheel in such a manner as to constrain the driving wheel to follow the cam contour, and thereby to move the burner parallel to the surface to be heated at a velocity determined by the shape of the cam plate.

. 2. Apparatus for heating metal articles, particularly toothed wheels. by means of the blow pipe flame for the purpose of subsequent hardening, which comprises a burner c'arriage movable parallel to the surface to be heated; an arm slldably mounted on the carriage and movable towards and from the'article, 'a fixed cam plate, and adriving wheel carried onthe arm, means for. rotating said driving wheel with a: constant velocity, a magnetic device connected with the wheel'in such a manner as to constrain the driving wheel to follow the cam contour, and thereby to move the burner parallel to the surface to be heated at a velocity determined by the shape ofsaid cam plate, a second fixed-cam plate an idle running wheel, also carried on said arm and adapted to follow the contour of said said arm.

HERMANN HOILER. 

